The perfect membrane should be transparent.

If the film is whitish and not completely transparent, it means that the acetic acid content in the transparent solution is not high.

The transparent liquid is prepared by Xia Lu himself, and the formula is glacial acetic acid and absolute ethanol, which is 1 to 9 for dilute and 3 to 7 for concentration.

Xia Lu soaked the membrane in the dilute transparent solution for 2 minutes, and then carefully took it out and soaked it in the concentrated transparent solution for 2 minutes.

The membrane must be handled with care, carelessness will lead to irreversible results.

Xia Lu took out the acetate film from the thick transparent solution, pasted it on the slide very gently, and blew it dry.

At this point, Xia Lu and Zhang Kai's biological experiments that took a morning came to an end.

"Your lab operation is very standardized, and this good habit should be maintained. Professor Xu said to Xia Lu.

Emotional valuation +18 from Professor Xu Mingchang.

"Understood, thank you for your guidance. Xia Lu began to clean up the experimental table, he did not deliberately brush Professor Xu Mingchang's emotional valuation, +18 was Professor Xu's voluntary contribution.

The division of labor between Xia Lu and Zhang Kai is clear, Xia Lu is the main practical operation, and Zhang Kai is the main data processing.

While Xia Lu cleaned up the experimental table, Zhang Kai calculated the serum protein content of each zone based on their experimental results, and answered two questions raised by Professor Xu on the experimental record paper: first, how to understand electrophoresis technology, and second, why can electrophoresis divide serum protein into several zones?

"You check, and if it's all right, write your name. Zhang Kai handed the experiment record paper to Xia Lu.

Xia Lu carefully reviewed Zhang Kai's experimental records, analysis of results, and answers to reflection questions.

Zhang Kai is a little clumsy in practice, but his written processing ability is croaking. As long as the experiment is completed and the materials are given to Zhang Kai, he can sort out a near-perfect experimental report in the shortest possible time.

"Very nice experimental record, Zhang Kai, your handwriting is so beautiful. Xia Lu wrote his name in the column of the experimenter on the experimental record paper.

The most important thing in being a human being is to see the strengths of others and face up to your own shortcomings. Zhang Kai said sincerely: "Xia Lu, in the future, the two of us will form a team, and the cooperation between the two of us can be described as seamless." ”

"Group, who made us roommates? Xia Lu agreed, he saw Zhang Kai's strengths.

Xia Lu's college life has become very regular, getting up at 6 o'clock in the morning every day, attending classes, doing experiments, self-study, and teacher-student tea parties. Classrooms, laboratories, libraries, tea rooms in the Plum Garden.

Physics knowledge valuation +322

Chemistry knowledge valuation +278

Biology knowledge is estimated at +300

Mathematical knowledge valuation +287

……

The results of Xia Lu's efforts are reflected in the system, and the valuation of various knowledge is constantly improving.

The improvement of knowledge valuation means that Xia Lu's understanding of these knowledge continues to deepen.

The most highly valued knowledge at the moment is physics at 2987 points.

When Xia Lu was in high school, the system set high school physics knowledge and junior high school physics knowledge.

After Xia Lu went to university, his college physics knowledge, high school physics knowledge, and junior high school physics knowledge were merged into physics knowledge. Other subjects and so on.

Before Xia Lu sold his knowledge of history, geography, and politics in high school, he now makes up for it by taking elective courses + self-study.

In addition to studying, Xia Lu actively participates in sports, and when he has free time, he will go to the swimming pool to practice his swimming skills under the guidance of the professional coach of the school swimming team.

Addicted to studies and physical exercise, Xia Lu goes home every weekend to reunite with his parents and play with his pet cat.

The system sets four girls, and Xia Lu and any one of them has an indescribable behavior, which can cancel out a forced exchange and gain 10,000 points.

After all, a person's energy is limited, and Xia Lu spends his time on studying, sports, family affection, and cats, so that he neglects the girls.

On Saturday, Zhengyuan Natatorium, a training venue rented by the Jiangcheng University swimming team.

Xia Lu in the pool swam hard, and Coach Mu on the shore shouted: "Xia Lu, 30 meters for a change of air!"

Xia Lu immediately turned his head to the left and changed his breath, and then held his breath and rushed the remaining 20 meters.

Coach Mu pinched his watch and looked at the results, 24.8 seconds.

"Xia Lu, you swim 50 times, you still have to get used to ventilating on the way, and you need to change your breath at least once. "Coach Mu is a retired swimming coach from the provincial team, and was invited by Jiangcheng University to train the school swimming team, and he is an experienced old coach.

The first thing any swimmer learns any kind of stroke, and the first thing they have to learn at the beginner stage is to breathe.

Xia Lu is no longer a beginner, but Coach Mu is still teaching him to ventilate.

In fact, Coach Mu's approach is more like a reminder.

Xia Lu must know how to ventilate, and he held his breath for the whole time in the 50-meter freestyle because he didn't want to ventilate.

"I think it's over, just hold your breath and do it to the end. Xia Lu climbed ashore and said.

24.8 seconds, that's a terrible result.

After all, at Coach Mu's forcible request, Xia Lu had just changed his breath on the way, which affected his swimming speed.

"You swim 50 meters and you can hold your breath the whole time. Can you swim 100 meters?" asked Coach Mu.

"You can't hold your breath for 100 meters. Xia Lu shook his head and asked, "I still have to swim 100 meters?"

Coach Mu said: "Have you ever seen a sprint freestyle swimmer who only swims 50 meters in a single event? ”

"Oh, okay, then I'll do another 100. By the way, Coach Mu, when is the next game?" Xia Lu asked.

Coach Mu: "In March next year, the city's universities will hold a joint sports meeting, and Xia Lu will focus on the 100 self and 50 self, and then represent Jiangcheng University in the competition." ”

Xia Lu made an OK gesture: "Okay, no problem." ”

Coach Mu added: "The ultimate goal of our team is to have a team member win the professional ranking in the men's sprint event at the National Universiade in September next year. Actually, the only people in our team who have this kind of potential are Xia Luyou and Lin Yu. Xia Lu, on the premise of not affecting your studies, I hope you can participate in the training of the swimming team more. ”

"Certainly, I really like swimming, Coach Mu, don't worry, I will work hard. After Xia Lu finished speaking, he jumped into the pool and swam again.

"Ventilation!"

"Pay attention to your body posture when you turn around!"

"Take another breath to the side!"

Coach Mu kept shouting technical essentials on the shore, and Xia Lu swam around in the pool.

Swimming, the question arises.

Xia Lu's 50-free best time was stuck at the 24-second mark, which was his result in the whole school sports meeting by holding his breath all the way.

In recent training, even if Xia Lu held his breath again the whole time, he couldn't swim under 24 seconds.

There are two reasons for this, first, Xia Lu may be a competitive player, and his competition performance is better than his training performance.

Second, Xia Lu's physical functions need to be further improved.

No matter what, you have to upgrade to the physical function level of the elite one-star before you can be sure to participate in the National Universiade.